diff options
Diffstat (limited to 'fs/nilfs2')
| -rw-r--r-- | fs/nilfs2/dir.c | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/fs/nilfs2/dir.c b/fs/nilfs2/dir.c index d748d9dce7..69ac866332 100644 --- a/fs/nilfs2/dir.c +++ b/fs/nilfs2/dir.c @@ -384,11 +384,39 @@ found: struct nilfs_dir_entry *nilfs_dotdot(struct inode *dir, struct folio **foliop) { - struct nilfs_dir_entry *de = nilfs_get_folio(dir, 0, foliop); + struct folio *folio; + struct nilfs_dir_entry *de, *next_de; + size_t limit; + char *msg; + de = nilfs_get_folio(dir, 0, &folio); if (IS_ERR(de)) return NULL; - return nilfs_next_entry(de); + + limit = nilfs_last_byte(dir, 0); /* is a multiple of chunk size */ + if (unlikely(!limit || le64_to_cpu(de->inode) != dir->i_ino || + !nilfs_match(1, ".", de))) { + msg = "missing '.'"; + goto fail; + } + + next_de = nilfs_next_entry(de); + /* + * If "next_de" has not reached the end of the chunk, there is + * at least one more record. Check whether it matches "..". + */ + if (unlikely((char *)next_de == (char *)de + nilfs_chunk_size(dir) || + !nilfs_match(2, "..", next_de))) { + msg = "missing '..'"; + goto fail; + } + *foliop = folio; + return next_de; + +fail: + nilfs_error(dir->i_sb, "directory #%lu %s", dir->i_ino, msg); + folio_release_kmap(folio, de); + return NULL; } ino_t nilfs_inode_by_name(struct inode *dir, const struct qstr *qstr) |